1. Field of the Invention
The present invention relates to the field of email and, more particularly, to the performance of dynamic set operations when specifying email recipients.
2. Description of the Related Art
Email plays a large part in personal and business communications. When sending an email to a large number of recipients, users must enter an identifier for each addressee and/or specify a distribution list containing a static group of previously defined addressees. Large groups of addressees and/or distribution lists can be difficult to manage. Many email applications have the ability to categorize addressees and distribution lists. This ability allows users to organize addressees and distribution lists into user defined recipient groups, such as “Family” or “Coworkers”. When graphically selecting recipient groups, users can choose to view only those recipients and distribution lists associated with a defined group.
Despite conventional organizational aids, email applications that support conventional distribution lists lock users into an all-or-nothing arrangement. The applications do not allow a user to send an email to a subset of addressees in a distribution list, such as excluding a specific email address from the list. Instead, users must resort to manually editing the distribution list members or manually selecting individual email addresses. This limitation can be tedious and frustrating to users who desire to send email to a large set of recipients that is similar but not identical to a set of addressees specified within an existing distribution list.
Another problem with many existing implementations of distribution lists is that users cannot combine multiple distribution lists to create a single list that includes all members without a duplication of email addresses. Users can select multiple distribution lists as recipients. However, if an email address appears in multiple lists, this recipient can be sent the email message multiple times. This amount of extraneous email can be taxing on the receiver's email system by consuming more space than necessary. In turn, these extraneous emails can cause the receiver's email inbox to reach capacity faster and, therefore, reject other pertinent messages.
To cope with these shortcomings, many users create a multiplicity of distribution lists with minor differences in an attempt to overcome the inherent static nature of conventional distribution lists. The quantity of modified distribution lists necessary to account for even the most probable permutations is astronomical and increases exponentially as the size and quantity of lists increase. These lists can consume additional storage space, which can degrade the overall performance of the email system. Additionally, the user is challenged with having to constantly decipher somewhat cryptic names often assigned to a plethora of similar distribution lists.